JP5326196B2 - Lead acid battery - Google Patents

Description

  The present invention relates to a lead-acid battery.

  Lead-acid batteries are used for various purposes such as vehicle engine starting and backup power supply. Among them, the start lead-acid battery supplies power to various electric and electronic devices mounted on the vehicle as well as power to the engine start cell motor. After the engine is started, the battery is charged by the alternator. Here, the output voltage and output current of the alternator are set so that charging and discharging are balanced and the SOC of the lead storage battery is maintained at approximately 100%.

  In most cases, the starting lead-acid battery is installed in the engine room. Therefore, since charging is performed in a high temperature atmosphere of 40 ° C. to 80 ° C., the storage battery is likely to be overcharged. As a result, water in the electrolytic solution is decomposed into oxygen and hydrogen gas by electrolysis and discharged out of the battery. As a result, the electrolyte level is lowered. Even when charging is not performed, the electrolytic solution level is also lowered by the evaporation of moisture from the electrolytic solution or the electrolytic solution mist filled in the battery being dissipated outside the battery.

  The decrease in the electrolyte in the liquid lead-acid battery results in a decrease in battery capacity due to corrosion of the negative electrode strap and oxidation of the negative electrode active material. Therefore, the electrolytic solution level is inspected, and when the liquid level falls below a specified level, water replenishment is performed so that the entire surface of the negative electrode strap and the negative electrode plate is immersed in the electrolytic solution.

  In order to save the labor of such water replenishment work, technical development for suppressing liquid reduction of the liquid lead-acid battery has been continuously performed. For example, the use of an alloy that does not contain Sb, such as a Pb—Ca alloy or a Pb—Sn alloy, that reduces hydrogen overvoltage as a lead alloy for a lead-acid battery grid, widely reduces the amount of liquid due to electrolysis. Are known.

  On the other hand, various studies have been made mainly from the viewpoint of improving the exhaust structure of lead-acid batteries in order to suppress the evaporation of water from the electrolyte and the loss of electrolyte mist filled in the battery due to the dissipation outside the battery. Has been done.

  For example, Patent Document 1 discloses that when exhausting oxygen / hydrogen gas generated from a cell to the outside of the battery, the exhaust path has a maze structure, and water vapor or electrolyte mist passes through the maze structure. A structure is shown in which water is condensed on the wall surface as water or an electrolytic solution, and these are refluxed into the cell.

Thus, by making the exhaust path of the lead storage battery have a labyrinth structure, it is possible to effectively suppress the reduction of the electrolyte due to the dissipation of water vapor or electrolyte mist to the outside of the battery.
JP-A-8-22815

  Although the structure shown in Patent Document 1 can suppress the decrease in the electrolyte due to the evaporation of the electrolyte and the discharge of the electrolyte mist, it can be caused by the self-discharge of the lead storage battery or the decomposition of water that progresses when the lead storage battery is charged. The decrease in electrolyte cannot be suppressed.

  Therefore, even if the reflux structure as in Patent Document 1 is adopted, liquid reduction cannot be prevented, and the electrolyte surface is lowered by long-term use, and a strap that connects electrode tabs of the same polarity is connected. There is a problem that the battery is exposed from the electrolytic solution, particularly, the strap portion of the negative electrode plate is corroded, the battery capacity is reduced, and the engine cannot be started.

  Furthermore, in a battery with a reflux structure on the lid, it is difficult to place a water faucet for rehydration because of the space on the lid and the problem of the lid structure, and even if the user perceives a decrease in the electrolyte level Replenishment work is impossible. As a result, when used without water replenishment work, internal disconnection occurred due to corrosion of the negative electrode strap, and the lead storage battery suddenly became unusable.

  The present invention provides a lead storage battery in which a reflux path for water and electrolyte is additionally disposed in the gas exhaust path provided inside the lid, as described above, and further suppresses reduction of the electrolyte and Even when the negative electrode strap is lowered and exposed from the electrolytic solution, the lead storage battery having further excellent maintenance-free property and reliability is provided by suppressing the corrosion of the negative electrode strap.

In order to solve the above-described problem, the invention according to claim 1 of the present invention uses a Pb—Ca alloy for each of the positive electrode lattice body and the negative electrode lattice body, and the entire surfaces of the positive electrode plate and the negative electrode plate are immersed in the electrolytic solution, respectively. An exhaust path for exhausting gas exhausted from the cell to the outside of the battery inside the lid joined to the positive electrode plate, the negative electrode plate, and the upper part of the battery case containing the electrolytic solution, Using a lead alloy that does not contain antimony in the strap for joining the same polarity of the positive electrode plate and the negative electrode plate, having a reflux path for refluxing moisture or electrolyte condensed in the path to the cell, An exhaust chamber continuously connected to the cell, provided at one end of the exhaust chamber with an opening for introducing gas from the cell to the exhaust chamber, and at the other end with a discharge path for discharging the gas out of the battery; The exhaust chamber has the exhaust. Has a bottom wall sloping downwardly from the roadside toward the opening side, said respective bottom wall and a ceiling wall facing the bottom wall provided with plate-like projections, the plate-like projection which projects from the bottom wall, the upper end ceiling It is connected to the bottom wall so that it is above the lower end of the plate-like projection hanging from the wall, and one end thereof is connected to one side wall of the exhaust chamber, and the other end is not connected to the other side wall. The lead-acid battery is characterized in that, in the plate-like protrusions adjacent to each other, the gaps narrower than the plate-like protrusions are alternately provided.

  Furthermore, the invention according to claim 2 of the present invention is the lead-acid battery according to claim 1, wherein the pole column is connected to the strap and is connected to the cell and a terminal provided outside the battery, and between adjacent cells. A lead alloy containing no antimony is used as a lead alloy for internal connection composed of a connecting body for connecting them together.

  According to the configuration of the present invention described above, since the liquid reduction of the lead storage battery is remarkably suppressed, and the corrosion of the negative electrode strap is suppressed, a lead storage battery that is remarkably excellent in maintenance-free property and reliability can be provided.

  As shown in FIG. 1, a lead storage battery 1 according to an embodiment of the present invention includes a positive electrode plate 2 having a Pb—Ca alloy positive electrode lattice, a negative electrode plate 3 having a Pb—Ca alloy negative electrode lattice, and a separator. 4 is housed in the cell chamber 6 a of the battery case 6 together with the electrolytic solution 5, and a lid 7 is joined to the upper part of the battery case 6.

  The lid 7 has an exhaust gas recirculation structure A having an exhaust path for exhausting the gas discharged from the cell 8 to the outside of the battery and a reflux path for returning moisture or electrolyte condensed in the exhaust path to the cell 8. doing. A configuration example of the exhaust gas recirculation structure A will be described later.

  The lead storage battery 1 of the present invention uses a lead alloy that does not contain antimony for the positive strap 9 for connecting the positive plates 2 and the negative strap 10 for connecting the negative plates 3. When antimony is contained in the negative electrode strap 10, the hydrogen overvoltage of the negative electrode strap 10 decreases, the generation of hydrogen gas on the negative electrode strap 10 is promoted, and the amount of liquid reduction increases. Further, when antimony is contained in the positive electrode strap 9, the antimony eluted in the electrolyte solution 5 is deposited on the negative electrode plate 3 along with the oxidation of the positive electrode strap 9, so that the hydrogen overvoltage of the negative electrode plate 3 is reduced. Similarly, the amount of liquid reduction increases.

  Moreover, the negative electrode potential at the time of charging shifts more preciously due to the decrease in hydrogen overvoltage at the negative electrode plate 3 and the negative electrode strap 10. When charging a lead-acid battery at a constant voltage, such as for ordinary automobiles and backups, the positive electrode potential shifts to noble as the negative electrode potential shifts to noble at the time of charging. The hydrogen overvoltage drop at the negative electrode plate 3 further proceeds.

  Such an action of reducing the hydrogen overvoltage of the negative electrode plate 3 of antimony contained on the positive electrode strap 9 side is hardly derived in the lead-acid battery in the initial state, but gradually increases with the use of the lead-acid battery.

  In the lead-acid battery of the present invention, liquid reduction due to evaporation of water in the electrolytic solution and dissipation of the electrolytic solution mist to the outside of the battery is suppressed by the exhaust gas recirculation structure A. Since it is suppressed by using the alloy which does not contain antimony for the strap 10, as a whole, the amount of liquid reduction is remarkably suppressed, and a lead storage battery which is remarkably excellent in maintenance-free property can be obtained.

  Moreover, the exposure from the electrolyte solution 5 of the positive electrode strap 9 and the negative electrode strap 10 is suppressed by the liquid reduction suppression effect by not including antimony in the positive electrode strap 9 and the negative electrode strap 10. In particular, corrosion may proceed in the negative electrode strap 10 exposed from the electrolytic solution 5, and the connection between the negative electrode strap 10 and the negative electrode plate 3 may be disconnected. Such a corrosion phenomenon in the negative electrode strap 10 is remarkable when the negative electrode lattice is made of a lead-calcium alloy and the negative electrode strap 10 is made of a lead-antimony alloy. Such a corrosion phenomenon is thought to be due to the presence of a compound of antimony and calcium.

  In the present invention, both the positive electrode strap 9 and the negative electrode strap 10 are made of lead alloys containing no antimony to suppress the liquid reduction itself, and even when the negative electrode strap 10 is exposed from the electrolytic solution 5 by reducing the liquid, Corrosion between the negative electrode strap 10 and the negative electrode plate 3 is suppressed, and a lead-acid battery having excellent maintenance reliability and the reliability of the connecting portion between the negative electrode strap 10 and the negative electrode plate 3 can be obtained.

  The structure of the present invention as described above is preferably applied to a lead storage battery having a structure in which water cannot be replenished to the cell chamber 6a due to the structure such as the absence of a liquid stopper. Even if liquid reduction progresses during use, water replenishment is impossible, and corrosion of the negative electrode strap 10 is suppressed even when the negative electrode strap 10 must be used in a state exposed from the electrolytic solution.

  In the present invention, both the positive electrode strap 9 and the negative electrode strap 10 do not contain antimony, but antimony is not present for the purpose of not reducing the hydrogen overvoltage of the negative electrode plate 3 and the negative electrode strap 10 and therefore hardly contributes to the reduction of the hydrogen overvoltage. The presence of moderate amounts of antimony (eg, less than about 50 ppm) is acceptable. In addition, as a lead alloy used for the positive electrode strap 9 and the negative electrode strap 10, a lead-tin alloy containing about 1 to 5 wt% of tin can be used.

  As a more preferable embodiment of the present invention, the positive pole 12 connected to the positive strap 9 for connecting the terminal 11 and the cell 8, and the connecting body 13 for connecting adjacent cells to each other are also used. A lead alloy such as a lead-tin alloy that does not contain antimony, similar to the negative electrode strap 10, can be used. By these, the increase in the liquid reduction amount resulting from antimony is suppressed. Although FIG. 1 shows a state in which the pole column 12 is connected to the positive strap 9 and the connection body 13 is connected to the negative strap 10, in the battery in which a plurality of cells 8 are connected in series, Depending on the position, the connection body 13 is connected to both the positive strap 9 and the negative strap 10, the connection body 13 is connected to the positive strap 9, and the pole column 12 is connected to the negative strap 10.

  A configuration example of the exhaust gas recirculation structure A shown in FIG. 1 will be described with reference to FIGS. 1 and 2. The exhaust gas recirculation structure A includes an exhaust chamber 21 provided in the lid 7 and an exhaust lid 22 that closes an upper portion of the exhaust chamber 21. At the bottom of the exhaust chamber 21, there is an opening 23 that communicates the exhaust chamber 21 and the cell chamber 6a. A discharge path 28 is provided at the uppermost part of the exhaust chamber 21, and the discharge paths 28 provided for each cell chamber 6 a merge to form a collective discharge path 29.

  The gas in the cell chamber 6 a is introduced into the lowermost portion of the exhaust chamber 21 through the opening 23 and is discharged to the discharge path 28 at the uppermost portion of the exhaust chamber 21. The gas discharged from the discharge path 28 is discharged out of the battery through the collective discharge path 29. Note that all the discharge paths 28 may be extended to the outside of the battery without providing the collective discharge path 29.

  In the present invention, in the exhaust chamber 21, the water vapor and the electrolyte mist contained in the gas are again converted into water droplets and electrolytic droplets, and refluxed into the cell chamber 6 a. In order to make water vapor and electrolyte mist into droplets, a plate-like protrusion 26 protruding from the bottom wall 24 and a plate-like protrusion 25 hanging from the ceiling wall 31 are provided in the exhaust chamber 21, and the exhaust gas flow is plate-like. The protrusions 25 and 26 are collided and brought into contact with each other, and the droplets are condensed on the plate-like protrusions 25 and 26.

  The condensed liquid droplets are guided to the opening 23 by the bottom wall 24 inclined downward from the discharge path 28 to the opening 23. Then, the droplet is refluxed into the cell chamber 6a through the opening 23. By providing a plurality of plate-like protrusions 25 and 26 with the bottom wall 24 and the ceiling wall 31 as the base, moisture in the exhaust gas such as water vapor and electrolyte mist is efficiently captured and recirculated, so that the cell chamber 6a is reduced. The liquid can be remarkably suppressed.

  The plate-like protrusions 26 having the bottom wall 24 as a base portion are provided over the entire width of the exhaust chamber 21, so that the liquid droplets cannot reach the opening 23. As shown in FIG. 2, the gap 26a is more preferable because the path length in the exhaust chamber 21 becomes longer by alternately providing the left and right between the adjacent plate-like protrusions 26, thereby improving the efficiency of recirculation. If the gap 26a is provided at the same position on the adjacent plate-like projections 26, the gas discharge path length becomes shorter, which is not preferable because the reflux efficiency is lowered.

  Although not shown in FIG. 2, in order to make the flow of droplets at the base of the plate-like protrusion 26 smoother, the gap 26 a side of the plate-like protrusion 26 than the one end fixed to the side wall 30 of the plate-like protrusion 26. It is preferable to incline one end of the head toward the opening 23 side.

  The shape of the opening 23 shown in FIG. 2 is a slit shape. The shape of the opening 23 is close to a circle, and depending on the setting of the area, the opening is closed by the droplet due to the interfacial tension, and the reflux of the droplet to the cell chamber 6a is prevented. Therefore, it is preferable to have a slit shape having an opening width such that the opening 23 is not blocked by the interfacial tension.

  According to the configuration of the present invention as described above, the gas from the cell 8 collides with the plate-like protrusion 26 protruded from the bottom wall 24 while the gas is discharged out of the battery, and the gas is left and right. Since the gas moves up and down by colliding with the plate-like protrusion 25 that hangs down from the ceiling wall 31, the apparent gas discharge path is extended as a whole, so that the reflux efficiency in the exhaust chamber 21 is improved. It becomes high and is preferable in suppressing liquid reduction.

  As described above, according to the configuration of the present invention, in the lead storage battery in which the exhaust path and the reflux structure are provided in the lid, the moisture reduction in the electrolytic solution is further suppressed, and the negative electrode strap becomes the electrolytic solution by such moisture reduction. Even when it is more exposed, it is possible to provide a lead storage battery in which corrosion of the negative electrode strap is suppressed, excellent in maintenance-free property, and excellent in reliability of the negative electrode strap.

Example 1
Hereinafter, the effects of the present invention will be described with reference to examples. A lead storage battery (80D26 type starting lead storage battery in JIS D5301) according to the present invention example and a comparative example was manufactured, and the amount of liquid reduction when the battery was charged while applying vibration to each lead storage battery was evaluated.

(Battery A of the present invention example)
The battery A of the present invention example is a lead storage battery according to the above-described embodiment of the present invention. An expanded lattice using lead-0.07 wt% calcium-1 wt% tin alloy was used for the positive electrode plate, and an expanded lattice using lead-0.07 wt% calcium-0.3 wt% tin alloy was used for the negative electrode plate. .

  As the separator, a microporous film in which silica and mineral oil were added to polyethylene resin was used, and this was made into a bag shape to enclose the positive electrode plate.

  As the positive electrode strap and the negative electrode strap, a lead-2.5 wt% tin alloy having an antimony content limited to less than 0.001 wt% was used. Moreover, the same lead-2.5 wt% tin alloy as the strap was used for the pole column and the connection body.

(Battery B of the present invention example)
In the battery B of the present invention, a lead-2.5 wt% antimony-0.2 wt% arsenic alloy is used as the lead alloy for the pole pole and connection body in the battery A of the present invention.

(Comparative battery C)
The battery C of the comparative example uses the lead-2.5 wt% antimony-0.2 wt% arsenic alloy as the lead alloy for the positive strap and the negative strap in the battery B of the present invention.

  While the above-described batteries A and B of the present invention and the battery C of the comparative example are continuously charged for 2000 hours at a charging voltage of 14.5 V (maximum charging current of 25 A) in a temperature atmosphere of 60 ° C., 1 G (30 Hz) The battery mass loss was measured as the amount of liquid reduction when vibration was applied in the vertical direction at the acceleration of).

  Table 1 shows the measurement results of the battery mass loss. In Table 1, the percentage of mass loss of the battery C of the comparative example is shown as 100%.

  From the results shown in Table 1, it can be seen that according to the present invention, in a lead storage battery having an exhaust gas recirculation structure on the lid, liquid reduction due to electrolysis is suppressed, and a lead storage battery excellent in maintenance-free property can be provided.

  Next, for the batteries A, B, and C described above, the electrolyte solution surface was set at a position 5 mm below the lower surface of the negative electrode strap so that the negative electrode strap was exposed from the electrolyte solution. 14.5V constant voltage charge was continuously performed for 2000 hours in a state where vibration was applied. After completion of charging, each battery was disassembled and the state of the negative electrode strap was observed. The results are shown in Table 2.

  As shown in Table 2, according to the example of the present invention, there was no corrosion of the negative electrode strap with disconnection as seen in the battery C according to the comparative example, and the reliability of the negative electrode strap was remarkably improved. I found out.

  Therefore, according to the present invention, it is possible to remarkably suppress the liquid reduction of the lead acid battery for automobiles, and to suppress the corrosion of the negative electrode strap even when the liquid reduction progresses and the negative electrode strap is exposed from the electrolytic solution. I understand.

  Since the present invention significantly reduces liquid reduction in the lead storage battery and improves the reliability of the negative electrode strap portion, it is suitable for liquid lead storage batteries for various uses including liquid start lead batteries. It is.

Sectional drawing which shows the lead acid battery of this invention The figure which shows the exhaust gas recirculation structure of the lead acid battery of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Lead acid battery 2 Positive electrode plate 3 Negative electrode plate 4 Separator 5 Electrolyte 6 Battery case 6a Cell chamber 7 Lid 8 Cell 9 Positive electrode strap 10 Negative electrode strap 11 Terminal 12 Polar column 13 Connector 21 Exhaust chamber 22 Exhaust lid 23 Opening 24 Bottom wall 25 26 Plate-like projections 26a Gap 28 Discharge path 29 Collective discharge path 30 Side wall 31 Ceiling wall A Exhaust gas recirculation structure

Claims (2)

The Pb—Ca—Sn alloy is used for each of the positive and negative grid bodies, and the entire surfaces of the positive and negative electrode plates are immersed in the electrolytic solution, and the positive and negative electrode plates and the electrolytic solution are accommodated therein. An exhaust path for discharging the gas discharged from the cell to the outside of the battery is provided inside the lid joined to the upper part of the battery case, and moisture or electrolyte solution condensed in the exhaust path is returned to the cell. Using a lead alloy that does not contain antimony in the strap for joining the same polarity of the positive electrode plate and the negative electrode plate,
An exhaust chamber connected to the cell is provided, an opening for introducing gas from the cell to the exhaust chamber is provided at one end of the exhaust chamber, and an exhaust passage for exhausting the gas to the outside of the battery is provided at the other end. The exhaust chamber has a bottom wall inclined downward from the discharge path side to the opening side, and plate-like projections are alternately provided on the bottom wall and the ceiling wall facing the bottom wall, respectively, and protruded from the bottom wall. The plate-like protrusion is connected to the bottom wall so that its upper end is above the lower end of the plate-like protrusion that hangs down from the ceiling wall, and one end thereof is connected to one side wall of the exhaust chamber, and the other end is A lead-acid battery, characterized in that the gaps that are not connected to the other side wall and have gaps and that are adjacent to each other are alternately provided with the gaps narrower than the plate-like protrusions . Antimony is not included in the lead alloy for internal connection consisting of a pole column connected to the strap and connected to the cell and a terminal provided outside the battery and a connection body for connecting adjacent cells to each other. The lead acid battery according to claim 1, wherein a lead alloy is used.

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